V. Kathavate, H. Sonagara, B. Kumar, I. Singh, K. Eswar Prasad
The indentation response of polycrystalline lead zirconate titanate (PZT) with varying ferroelastic domain configurations is investigated using nano and micro indentation. In the fully depoled state (with completely random domain configurations), PZT exhibit higher hardness, H as compared to poled PZT. Severe cracking is observed at the imprint corners at high indentation loads and the ferro-elastic domain configurations are visualized in the vicinity and ahead of the crack using piezoresponse force microscopy. The domains remain fully plastic in the regions from where the crack has propagated and just ahead of the crack while farther from the crack their remain elastic. The results are rationalized using remanent strain, ε r results highlight the toughening mechanisms in the as poled PZTs. and converse piezocharge coefficient, d *33 measured around microcrack. The results highlight the toughening mechanisms in the as poled PZTs.
{"title":"Direct Observations of Changes in Ferroelectric Domain Configurations Around the Indentation and Ahead of the Crack Front","authors":"V. Kathavate, H. Sonagara, B. Kumar, I. Singh, K. Eswar Prasad","doi":"10.2139/ssrn.3831029","DOIUrl":"https://doi.org/10.2139/ssrn.3831029","url":null,"abstract":"The indentation response of polycrystalline lead zirconate titanate (PZT) with varying ferroelastic domain configurations is investigated using nano and micro indentation. In the fully depoled state (with completely random domain configurations), PZT exhibit higher hardness, <i>H</i> as compared to poled PZT. Severe cracking is observed at the imprint corners at high indentation loads and the ferro-elastic domain configurations are visualized in the vicinity and ahead of the crack using piezoresponse force microscopy. The domains remain fully plastic in the regions from where the crack has propagated and just ahead of the crack while farther from the crack their remain elastic. The results are rationalized using remanent strain, <i> ε <sup>r</sup> </i> results highlight the toughening mechanisms in the as poled PZTs. and converse piezocharge coefficient, <i>d <sup>*</sup>33</i> measured around microcrack. The results highlight the toughening mechanisms in the as poled PZTs.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85788817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wenli Xie, Xinxin Jiang, Ge Xu, Xuhui Xu, Quan Gao, Bin Cui, De-sheng Liu, Dongmei Li
Doping earth-abundant elements in noble metal to form alloy can lower the material cost and may remove adhesive reaction products and improve the electrochemical characters to overcome the “catalyst poisoning”. Herein, we investigated the effects of one atom substitution in a Pt7 cluster with a carbon group element (X = C, Si, or Ge), forming a Pt6X cluster, and the interaction with an H2O molecule by density functional theory. Based on the reaction path analysis, we confirmed that the Pt6X cluster, superior to the Pt7 cluster, could directly catalyze the decomposition of H2O into free H2 and O+Pt6X complex. Moreover, by capturing a CO molecule, the CO@O+Pt6X complex subsequently passed a low energy barrier, returning to the isolated Pt6X and a free CO2 molecule, ultimately eliminating the reuse problem of the “poisoned catalyst”.
{"title":"H2 Generation by Water Dissociation on Nano Alloy Clusters","authors":"Wenli Xie, Xinxin Jiang, Ge Xu, Xuhui Xu, Quan Gao, Bin Cui, De-sheng Liu, Dongmei Li","doi":"10.2139/ssrn.3929881","DOIUrl":"https://doi.org/10.2139/ssrn.3929881","url":null,"abstract":"Doping earth-abundant elements in noble metal to form alloy can lower the material cost and may remove adhesive reaction products and improve the electrochemical characters to overcome the “catalyst poisoning”. Herein, we investigated the effects of one atom substitution in a Pt7 cluster with a carbon group element (X = C, Si, or Ge), forming a Pt6X cluster, and the interaction with an H2O molecule by density functional theory. Based on the reaction path analysis, we confirmed that the Pt6X cluster, superior to the Pt7 cluster, could directly catalyze the decomposition of H2O into free H2 and O+Pt6X complex. Moreover, by capturing a CO molecule, the CO@O+Pt6X complex subsequently passed a low energy barrier, returning to the isolated Pt6X and a free CO2 molecule, ultimately eliminating the reuse problem of the “poisoned catalyst”.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"99 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81374560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract We report crystallographic orientation dependent fracture behavior in tantalum single crystals with the tensile axes oriented close to [100], [110] and [111] directions. Three tantalum single crystals were deformed in quasi-static, uniaxial tension and their fracture surfaces were characterized. To understand different deformation modes and failure mechanisms, crystal plasticity-finite element (CP-FE) simulations were performed. Both experiments and CP-FE simulations showed strong strain localization and shear banding in the ~[100] specimen, little rotation and profuse necking in the ~[110] specimen, and significant crystal rotations associated with shear-dominated behavior in the ~[111] single crystal. In addition, voids were observed in fracture surfaces of ~[100] and ~[111] single crystals while the ~[110] specimen was void-free. The failure processes of these single crystals showed that dislocation boundaries are necessary for void nucleation in pure tantalum. This work demonstrates strong effects of crystallographic orientations in failure behaviors.
{"title":"Crystallographic Orientation Dependent Fracture Behavior in Tantalum Single Crystals","authors":"Hojun Lim, P. Noell, J. Carroll","doi":"10.2139/ssrn.3680336","DOIUrl":"https://doi.org/10.2139/ssrn.3680336","url":null,"abstract":"Abstract We report crystallographic orientation dependent fracture behavior in tantalum single crystals with the tensile axes oriented close to [100], [110] and [111] directions. Three tantalum single crystals were deformed in quasi-static, uniaxial tension and their fracture surfaces were characterized. To understand different deformation modes and failure mechanisms, crystal plasticity-finite element (CP-FE) simulations were performed. Both experiments and CP-FE simulations showed strong strain localization and shear banding in the ~[100] specimen, little rotation and profuse necking in the ~[110] specimen, and significant crystal rotations associated with shear-dominated behavior in the ~[111] single crystal. In addition, voids were observed in fracture surfaces of ~[100] and ~[111] single crystals while the ~[110] specimen was void-free. The failure processes of these single crystals showed that dislocation boundaries are necessary for void nucleation in pure tantalum. This work demonstrates strong effects of crystallographic orientations in failure behaviors.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82897475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Bagheri, H. Kamali, Erfan Kamali, S. Hossein Nedjad
Quenched and tempered Fe-9Ni (wt. %) steels have been widely used in cryogenic applications. For the first time, the formation of nodular bainite in an Fe-9Ni-0.06C (wt. %) steel during isothermal transformation at 550 and 500 °C for 24 h is reported. Electron microscopy revealed that proeutectoid ferrite forms predominantly by a massive transformation at prior austenite grain boundaries or at intragranular inclusions as the first stage of austenite decomposition. Then, nodular bainite composed of a ferritic matrix and rows of fine cementite precipitates forms by interphase boundary precipitation during decomposition of adjacent C-enriched austenite. Both the Bagarayatskii and Isaichev orientation relationships between ferrite and cementite were observed. Also, the microhardness of nodular bainite in the sample transformed at 500 °C (214 ± 4 VHN) was higher than that in the sample transformed at 550 °C (195 ± 5 VHN), due to smaller sizes of cementite precipitates in the former.
{"title":"Formation of Nodular Bainite in a Fe-9.10ni-0.06c (Wt. %) Alloy: A New Microstructure for Cryogenic Steels","authors":"Y. Bagheri, H. Kamali, Erfan Kamali, S. Hossein Nedjad","doi":"10.2139/ssrn.3893497","DOIUrl":"https://doi.org/10.2139/ssrn.3893497","url":null,"abstract":"Quenched and tempered Fe-9Ni (wt. %) steels have been widely used in cryogenic applications. For the first time, the formation of nodular bainite in an Fe-9Ni-0.06C (wt. %) steel during isothermal transformation at 550 and 500 °C for 24 h is reported. Electron microscopy revealed that proeutectoid ferrite forms predominantly by a massive transformation at prior austenite grain boundaries or at intragranular inclusions as the first stage of austenite decomposition. Then, nodular bainite composed of a ferritic matrix and rows of fine cementite precipitates forms by interphase boundary precipitation during decomposition of adjacent C-enriched austenite. Both the Bagarayatskii and Isaichev orientation relationships between ferrite and cementite were observed. Also, the microhardness of nodular bainite in the sample transformed at 500 °C (214 ± 4 VHN) was higher than that in the sample transformed at 550 °C (195 ± 5 VHN), due to smaller sizes of cementite precipitates in the former.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"61 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91475459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Bi2O3-B2O3-CaF2-EuF3 (BiBCEu) glass and glass-ceramics were prepared by a controlled heat treatment method for efficient orange-red laser applications and characterized through X-ray diffraction, Raman, transmission electron microscopy, photoluminescence excitation, emission and fluorescence decay studies. The BiBCEu glass-ceramics containing Bi3B5O12 and CaF2 nanocrystallites exhibit intense orange-red luminescence through Eu3+:5D0 → 7F2 (616 nm) transition when excited at 396 nm wavelength. The radiative parameters like radiative emission probability (AR), luminescence branching-ratio (bR) and radiative decay time (τR) were determined using the intensities of Eu3+: 5D0 → 7FJ (J = 1, 2, 4) emission transitions following the Judd-Ofelt theory. The chromaticity coordinates of BiBCEu glass-ceramic heat treated at 575oC for 10 hours are situated in the orange-red part of the CIE colour diagram. The observed results confirm that BiBCEu glass-ceramic obtained by heat treatment at 575oC for 10 hours is more favourable for solid state orange-red laser applications.
{"title":"Bi2O3-B2O3-CaF2-EuF3 Glass-Ceramics for Efficient Orange-Red Laser Applications","authors":"Chinna Jamalaiah Bungala, Madhu Napa, Venkata Rao Kasukurthi, Pavani Krishnapuram","doi":"10.2139/ssrn.3901725","DOIUrl":"https://doi.org/10.2139/ssrn.3901725","url":null,"abstract":"The Bi2O3-B2O3-CaF2-EuF3 (BiBCEu) glass and glass-ceramics were prepared by a controlled heat treatment method for efficient orange-red laser applications and characterized through X-ray diffraction, Raman, transmission electron microscopy, photoluminescence excitation, emission and fluorescence decay studies. The BiBCEu glass-ceramics containing Bi3B5O12 and CaF2 nanocrystallites exhibit intense orange-red luminescence through Eu3+:5D0 → 7F2 (616 nm) transition when excited at 396 nm wavelength. The radiative parameters like radiative emission probability (AR), luminescence branching-ratio (bR) and radiative decay time (τR) were determined using the intensities of Eu3+: 5D0 → 7FJ (J = 1, 2, 4) emission transitions following the Judd-Ofelt theory. The chromaticity coordinates of BiBCEu glass-ceramic heat treated at 575oC for 10 hours are situated in the orange-red part of the CIE colour diagram. The observed results confirm that BiBCEu glass-ceramic obtained by heat treatment at 575oC for 10 hours is more favourable for solid state orange-red laser applications.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"82 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90192491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuliang Zhao, Dong-Won Song, Haoliang Wang, Lijia Chen, Zhenzhong Sun, T. Zhai, Ya-nan Fu, Yao Wang, Shuhong Liu, Yong Du, Weiweng Zhang
Al-5Ti-1B is commonly added to the Al alloys for grain refinement, which also affects the type, size, morphology, and formation sequence of Fe-rich intermetallic phases. The underlying nucleation and growth mechanism of Fe-rich phases under the influence of Al-5Ti-1B during the solidification of Al-Cu-Fe(-Si) alloys were systematically studied by thermodynamic calculation, and with scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), focused ion beam (FIB) coupled with transmission electron microscopy (TEM), and in-situ synchrotron X-ray radiography. The SEM and in-situ synchrotron X-ray radiography experiments revealed that the Al-5Ti-1B addition significantly reduced the size and number of primary Al3(CuFe) phases. and refined the size of α-Fe in Al-Cu-Fe-Si alloy without changing their type. This was caused by Ti solute atoms in Al melts, which limiting the nucleation and growth of primary Al3(CuFe) phases during solidification. The FIB and TEM results showed that the prior formed TiB2 particles or/and newly-formed aluminium oxide were nucleate sites for Al6(CuFe) phase and α-Fe phase in Al-Cu-Fe alloy and Al-Cu-Fe-Si alloy, respectively. The Edge-to-Edge model and orientation relationship further confirmed the experimental results. In addition, V diffusion into TiB2 particles in the Al melts to form (TiV)B2 particles and lowering the interfacial energy enhance the heterogenous nucleation for Fe-rich phases.
{"title":"Revealing the Nucleation and Growth Mechanisms of Fe-Rich Phases in Al-Cu-Fe(-Si) Alloys Under the Influence of Al-Ti-B","authors":"Yuliang Zhao, Dong-Won Song, Haoliang Wang, Lijia Chen, Zhenzhong Sun, T. Zhai, Ya-nan Fu, Yao Wang, Shuhong Liu, Yong Du, Weiweng Zhang","doi":"10.2139/ssrn.3919733","DOIUrl":"https://doi.org/10.2139/ssrn.3919733","url":null,"abstract":"Al-5Ti-1B is commonly added to the Al alloys for grain refinement, which also affects the type, size, morphology, and formation sequence of Fe-rich intermetallic phases. The underlying nucleation and growth mechanism of Fe-rich phases under the influence of Al-5Ti-1B during the solidification of Al-Cu-Fe(-Si) alloys were systematically studied by thermodynamic calculation, and with scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), focused ion beam (FIB) coupled with transmission electron microscopy (TEM), and in-situ synchrotron X-ray radiography. The SEM and in-situ synchrotron X-ray radiography experiments revealed that the Al-5Ti-1B addition significantly reduced the size and number of primary Al3(CuFe) phases. and refined the size of α-Fe in Al-Cu-Fe-Si alloy without changing their type. This was caused by Ti solute atoms in Al melts, which limiting the nucleation and growth of primary Al3(CuFe) phases during solidification. The FIB and TEM results showed that the prior formed TiB2 particles or/and newly-formed aluminium oxide were nucleate sites for Al6(CuFe) phase and α-Fe phase in Al-Cu-Fe alloy and Al-Cu-Fe-Si alloy, respectively. The Edge-to-Edge model and orientation relationship further confirmed the experimental results. In addition, V diffusion into TiB2 particles in the Al melts to form (TiV)B2 particles and lowering the interfacial energy enhance the heterogenous nucleation for Fe-rich phases.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88144671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: Fracture of denture base made of Polymethylmethacrylate (PMMA) is a common clinical problem. To overcome this problem, several ways are used for reinforcement the PMMA . No information is available in the dental literature regarding the effect of incorporating basalt fibers on the mechanical properties of the PMMA. This study therefore investigated the flexural properties of heat-polymerized denture base acrylic resin reinforced with untreated chopped basalt fibers, and with monomer, silane, or phosphoric acid- treated chopped basalt fibers.
Methods: Sample was equally divided into five groups: group C (unreinforced with basalt fibers), group UBF (reinforced with untreated basalt fibers), group MBF (reinforced with monomer treated basalt fibers), group SBF (reinforced with silanized basalt fibers) and group PhABF (reinforced with basalt fibers treated by phosphoric acid 35%). A 3-point bending test was carried out for the test specimens with a universal testing machine.
Results: Flexural strength of Group MBF (83.71 ± 2.19)MPa and SBF (73.37 ± 2.1)MPa significantly increased in comparison of Group C (67.13 ± 1.60)MPa and the MBF group recorded the highest flexural strength.
Conclusions: Reinforcement the PMMA with monomer treated basalt fibers can be recommended.
{"title":"Flexural Properties of a Heat - Polymerized Polymethyl Methacrylate Denture Resin Reinforced with Basalt Fibers","authors":"Alaa'a Salloum","doi":"10.2139/ssrn.3876088","DOIUrl":"https://doi.org/10.2139/ssrn.3876088","url":null,"abstract":"Background: Fracture of denture base made of Polymethylmethacrylate (PMMA) is a common clinical problem. To overcome this problem, several ways are used for reinforcement the PMMA . No information is available in the dental literature regarding the effect of incorporating basalt fibers on the mechanical properties of the PMMA. This study therefore investigated the flexural properties of heat-polymerized denture base acrylic resin reinforced with untreated chopped basalt fibers, and with monomer, silane, or phosphoric acid- treated chopped basalt fibers. <br><br>Methods: Sample was equally divided into five groups: group C (unreinforced with basalt fibers), group UBF (reinforced with untreated basalt fibers), group MBF (reinforced with monomer treated basalt fibers), group SBF (reinforced with silanized basalt fibers) and group PhABF (reinforced with basalt fibers treated by phosphoric acid 35%). A 3-point bending test was carried out for the test specimens with a universal testing machine. <br><br>Results: Flexural strength of Group MBF (83.71 ± 2.19)MPa and SBF (73.37 ± 2.1)MPa significantly increased in comparison of Group C (67.13 ± 1.60)MPa and the MBF group recorded the highest flexural strength. <br><br>Conclusions: Reinforcement the PMMA with monomer treated basalt fibers can be recommended.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91100446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Khobragade, A. Swiderska-Sroda, W. Łojkowski, P. N. Babu, S. Pal, T. Maity, D. Roy
Graphene reinforced Cu-based nanocomposite was synthesized using high-pressure (~8 GPa) sintering or HPS. The HPS at 300°C processed composites successfully achieved 96% of relative density with 84% IACS improvement in electrical conductivity. Scanning and transmission electron microscopy showed that graphene reinforced uniformly and good combination between graphene and Cu matrix. A significant increase in nanohardness (~2.4GPa) and Young’s modulus (~94GPa) was retained during straining by HPS. Molecular dynamics (MD) simulations on graphene-reinforced nanocrystalline (NC) Cu (Gr-NC Cu) has exhibited higher nanohardness and Young’s modulus than NC Cu, and the MD results are well agreed with experimental data. The structural and defects evolution of NC Cu and Gr-NC Cu specimens has been investigated under the nanoindentation process.
采用高压(~ 8gpa)烧结或HPS法制备了石墨烯增强铜基纳米复合材料。HPS在300°C下加工的复合材料成功地实现了96%的相对密度，电导率提高了84%。扫描电镜和透射电镜显示石墨烯增强均匀，石墨烯与Cu基体结合良好。在HPS拉伸过程中，材料的纳米硬度(~2.4GPa)和杨氏模量(~94GPa)均有显著提高。石墨烯增强纳米晶(NC) Cu (Gr-NC Cu)的纳米硬度和杨氏模量均高于NC Cu，分子动力学模拟结果与实验数据吻合较好。研究了纳米压痕过程中NC Cu和Gr-NC Cu试样的结构和缺陷演变。
{"title":"Dislocation Entangled Mechanisms and 3D-2D Interface in Copper-Graphene Nanocomposite Fabricated by High-Pressure Sintering","authors":"N. Khobragade, A. Swiderska-Sroda, W. Łojkowski, P. N. Babu, S. Pal, T. Maity, D. Roy","doi":"10.2139/ssrn.3845645","DOIUrl":"https://doi.org/10.2139/ssrn.3845645","url":null,"abstract":"Graphene reinforced Cu-based nanocomposite was synthesized using high-pressure (~8 GPa) sintering or HPS. The HPS at 300°C processed composites successfully achieved 96% of relative density with 84% IACS improvement in electrical conductivity. Scanning and transmission electron microscopy showed that graphene reinforced uniformly and good combination between graphene and Cu matrix. A significant increase in nanohardness (~2.4GPa) and Young’s modulus (~94GPa) was retained during straining by HPS. Molecular dynamics (MD) simulations on graphene-reinforced nanocrystalline (NC) Cu (Gr-NC Cu) has exhibited higher nanohardness and Young’s modulus than NC Cu, and the MD results are well agreed with experimental data. The structural and defects evolution of NC Cu and Gr-NC Cu specimens has been investigated under the nanoindentation process.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"51 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91473573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ruitong Zhu, Zihua Zhao, Jun Cao, Haichao Li, Li Ma, K. Zhou, Zhiming Yu, Qiu-ping Wei
With the increasing number of diabetic patients, considerable attention has been paid to developing metal nanomaterial glucose sensors for detecting under physiological pH conditions. In this work, Pt-Ni modified boron-doped diamond (BDD) electrodes were fabricated and achieved a continuous and stable response to glucose under neutral pH conditions. Besides, effects of the electrochemical deposition sequence on the morphology and electrocatalytic properties of the Pt-Ni bimetal had been found. Electrochemical performance tests showed that the Pt-Ni bimetal clusters prepared by the co-deposition (one step) method had higher stability and sensitivity for the glucose detection than those prepared by the two-step deposition method. The loss of the oxidation peak current of PtNi-BDD is 21.74% after 200 consecutive cyclic voltammetry cycles (2400 s). While Ni/Pt-BDD and Pt-BDD only maintained 55.8% and 60.03% of their initial current response after continuous 1200 s cyclic voltammetry. In addition, the sensitivity of PtNi-BDD was 110.375 μA cm -1 mm -1 in the range of 2-12 mM glucose concentration, which was 5.966, 15.49, and 6.13 times higher than that of Pt/Ni-BDD, Ni/Pt-BDD, and single metal Pt, respectively.
随着糖尿病患者数量的不断增加，开发用于生理pH条件下检测的金属纳米材料葡萄糖传感器备受关注。在这项工作中，制备了Pt-Ni修饰的掺硼金刚石(BDD)电极，并在中性pH条件下实现了对葡萄糖的连续稳定响应。此外，还发现了电化学沉积顺序对Pt-Ni双金属形貌和电催化性能的影响。电化学性能测试表明，一步共沉积法制备的Pt-Ni双金属团簇比两步共沉积法制备的Pt-Ni双金属团簇具有更高的葡萄糖检测稳定性和灵敏度。连续200次循环伏安(2400 s)后，PtNi-BDD氧化峰电流损失21.74%，而连续1200 s循环伏安后，Ni/Pt-BDD和Pt-BDD氧化峰电流仅维持初始电流响应的55.8%和60.03%。在2 ~ 12 mm葡萄糖浓度范围内，PtNi-BDD的灵敏度为110.375 μA cm -1 mm -1，分别是Pt/Ni- bdd、Ni/Pt- bdd和单金属Pt的5.966、15.49和6.13倍。
{"title":"Effect of Pt-Ni Deposition Sequence in PtNi-Modified Boron-Doped Diamond on Catalytic Performance for Glucose Oxidation Under Neutral pH Conditions","authors":"Ruitong Zhu, Zihua Zhao, Jun Cao, Haichao Li, Li Ma, K. Zhou, Zhiming Yu, Qiu-ping Wei","doi":"10.2139/ssrn.3920309","DOIUrl":"https://doi.org/10.2139/ssrn.3920309","url":null,"abstract":"With the increasing number of diabetic patients, considerable attention has been paid to developing metal nanomaterial glucose sensors for detecting under physiological pH conditions. In this work, Pt-Ni modified boron-doped diamond (BDD) electrodes were fabricated and achieved a continuous and stable response to glucose under neutral pH conditions. Besides, effects of the electrochemical deposition sequence on the morphology and electrocatalytic properties of the Pt-Ni bimetal had been found. Electrochemical performance tests showed that the Pt-Ni bimetal clusters prepared by the co-deposition (one step) method had higher stability and sensitivity for the glucose detection than those prepared by the two-step deposition method. The loss of the oxidation peak current of PtNi-BDD is 21.74% after 200 consecutive cyclic voltammetry cycles (2400 s). While Ni/Pt-BDD and Pt-BDD only maintained 55.8% and 60.03% of their initial current response after continuous 1200 s cyclic voltammetry. In addition, the sensitivity of PtNi-BDD was 110.375 μA cm -1 mm -1 in the range of 2-12 mM glucose concentration, which was 5.966, 15.49, and 6.13 times higher than that of Pt/Ni-BDD, Ni/Pt-BDD, and single metal Pt, respectively.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89555903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soichiro Fujiwara, Yuta Yoshizaki, A. Kuzuya, Y. Ohya
Injectable polymers (IPs) exhibiting in situ hydrogel formation have attracted attention as vascular embolization and postoperative adhesion prevention materials. When using them for such purposes, attribution of tissue adhesion property to the hydrogel is important. We previously reported a temperature-responsive biodegradable IP system using triblock copolymers of poly(ε-caprolactone-co-glycolic acid) and poly(ethylene glycol) (tri-PCGs). Recently, we developed IP systems containing acrylate-capped tri-PCG (tri-PCG-Acryl) and polythiol compound (DPMP)-loaded tri-PCG. This IP system exhibit temperature-responsive gelation, where chemical cross-links were formed via thiol-ene reaction. The duration of gel state under physiological conditions and its physical properties could be controlled by changing the content of tri-PCG-Acryl and DPMP in the system. In this study, the addition of aldehyde-modified Pluronic (PL-CHO) was investigated for attributing tissue adhesive properties to the IP system. This IP system containing PL-CHO showed high tissue adhesive properties by Schiff base formation between the aldehyde groups and the biological tissue surface. We evaluated the possibility of using IP system as vascular embolization materials and postoperative adhesion prevention materials. The IP system showed good embolization performance in blood vessels, resisting pressure. The IP hydrogel remained at the administration site in the abdominal space for 2 days and showed effective adhesion prevention performance.
{"title":"Temperature-Responsive Biodegradable Injectable Polymers Having Tissue Adhesive Properties for Biomedical Materials","authors":"Soichiro Fujiwara, Yuta Yoshizaki, A. Kuzuya, Y. Ohya","doi":"10.2139/ssrn.3855768","DOIUrl":"https://doi.org/10.2139/ssrn.3855768","url":null,"abstract":"Injectable polymers (IPs) exhibiting <i>in situ</i> hydrogel formation have attracted attention as vascular embolization and postoperative adhesion prevention materials. When using them for such purposes, attribution of tissue adhesion property to the hydrogel is important. We previously reported a temperature-responsive biodegradable IP system using triblock copolymers of poly(ε-caprolactone-<i>co</i>-glycolic acid) and poly(ethylene glycol) (tri-PCGs). Recently, we developed IP systems containing acrylate-capped tri-PCG (tri-PCG-Acryl) and polythiol compound (DPMP)-loaded tri-PCG. This IP system exhibit temperature-responsive gelation, where chemical cross-links were formed via thiol-ene reaction. The duration of gel state under physiological conditions and its physical properties could be controlled by changing the content of tri-PCG-Acryl and DPMP in the system. In this study, the addition of aldehyde-modified Pluronic (PL-CHO) was investigated for attributing tissue adhesive properties to the IP system. This IP system containing PL-CHO showed high tissue adhesive properties by Schiff base formation between the aldehyde groups and the biological tissue surface. We evaluated the possibility of using IP system as vascular embolization materials and postoperative adhesion prevention materials. The IP system showed good embolization performance in blood vessels, resisting pressure. The IP hydrogel remained at the administration site in the abdominal space for 2 days and showed effective adhesion prevention performance.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74270245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：